MIS Ch. 5 Flashcards
Database
A self-describing COLLECTION of integrated RECORDS
What is the Purpose of a Database?
To KEEP TRACK of things
Columns
Fields
Rows
Records
Table
File
Key/ Primary Key
A column or group of columns that identifies a unique row in a table
Metadata
Data that describes data
Foreign Keys
Keys of a different table than the one in which they reside
Relational Databases
Databases that carry their data in the form of tables and represent relationships using foreign keys
Database Management System (DBMS)
A PROGRAM used to create, process, & administer a database
• Ex: DB2, Access, SQL Server, & Oracle Database
Structured Query Language (SQL)
And international standard language for processing a database
Database Administration
Used to set up a SECURITY system involving user accounts, passwords, permissions, and limits for processing the database
Database Application
A COLLECTION of forms, reports, queries, & application programs that serves as an INTERMEDIARY between users & database data
Graphical Queries
CRITERIA are created when the user clicks on a graphic.
Multi-User Processing
Multiple users processing the same database
Lost-Update Problem
Two users update the same data item, but only one of those changes is recorded in the data.
Entity-Relationship (E-R) Data Model
A TOOL for CONSTRUCTING data models by defining the entities that will be stored in the database and the relationships among those entities
Entity
Something that USERS want to TRACK
• Ex: Order, Customer, Salesperson, Item
Attributes
Describe characteristics of the entity
• Ex (for Order entity): OrderNumber, OrderDate, SubTotal, Tax, Total
Identifier
An ATTRIBUTE or group of attributes whose value is associated with only ONE ENTITY instance
Relationships
Associations among entities or entity instances in an E-R model, or an association among rows of a table in a relational database
Crow’s Feet
LINES on an entity-relationship diagram that indicate a 1:N relationship between two entities
Crow’s-Foot Diagram
A type of entity-relationship diagram that uses a crow’s foot symbol to designate a 1:N relationship
Entity-Relationship (E-R) Diagram
A type of diagram used by database DESIGNERS to DOCUMENT entities and their relationships to each other
1:N
One-to-many relationship
N:M
Many-to-many relationship
Normalization
The process of converting a poorly structured table into two or more well-structured tables
Maximum Cardinality
The maximum number of entities that can be involved in a relationship
Minimum Cardinality
The minimum number of entities required in a relationship
Data Integrity Problem
When data items DISAGREE with one another
• Ex: two different names for the same customer
Normal Forms
Forms of tables that remove duplicated data and other problems
MongoDB
And open-source, document-oriented, non-relational DBMS
NoSQL Databases
NON-RELATIONAL databases that support very high TRANSACTION RATES processing SIMPLE data structures, replicated on many servers in the cloud
Data Model
Describes the data & relationships that will be stored in the database
